<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
  </head>
  <body>
    <table>
      <thead>
        <tr>
          <th>a</th>
          <th>b</th>
          <th>c</th>
        </tr>
        <tr>
          <th>d</th>
          <th>e</th>
          <th>f</th>
        </tr>
        <tr>
          <th>g</th>
          <th>h</th>
          <th>i</th>
        </tr>
      </thead>
      <tbody></tbody>
    </table>
  </body>
</html>
